Method for producing a sharply bent corner in a plate



May 26, 1953 B. J. VOSLAMBER 2,639,495

METHOD FOR PRODUCING A SHARPLY BENT CORNER IN A PLATE Filed July 16, 1948 2 Sheets-Sheet l a I F'|G.l

PIC-3.2 FIG 3 B. J. VOSLAMBER 2,639,495-

May 26, 1953 METHOD FOR PRODUCING A SHARPLY BENT CORNER IN A PLATE 2 Sheets-Sheet 2 Filed July 16, 1948 FIE-3.5

Patented May 26, 1953 METHOD FOR PRODUCING A SHARPLY BENT CORNER IN A PLATE Berend J Voslamber, Hoogkerk,.;Netherlands,.as-

signer to. N. V. Betonfabriek" De Meteoor, De Steeg',.; Netherlands, a company, ofthe, Nether.-

lands,

Application 'July- 16, 1948, Serial No 39;074- Inft'hei. N etherlands- July 28, 1947 I BCIaims.

This invention relates. towa, method for producing a sharply bent corner in a plate.

When bending a plate in cold state to a right angle generally. a; morewor; less rounded corner is obtainedwhich ior various applications, e. g. for

metal floor plates or tiles is not desired.

According to the present invention asharp ly bent corner is-obtained by "bending a plate in cold state-toa right angle. To this end the blank isfirst subjected to a I preliminary shaping operation for bendinga a marginal portion of i the plate to a more or lessrounded corner; clamping or gripping-the-plate at its flat or base-portion to prevent dimensionaldisplacement thereof, supportingthe-plate w-iththeedge of its'flanged end portion on anabutment and clamping or grippingsaid flanged-end portion between a core member and a-inovable clamping member, whereafter the material at the preliminarilybent rounded corner is;up-setgtogasharply bent corner by means of an up-settingpunch. The excess of material needed for said up-setting, offthe corner maye. g. be obtained by formingduring the preliminary shaping operation an inclined bent region between the flat portion and the flanged portion, whereafter said inclined bent region is flattened when the edge of the flanged portion is supported on the abutment.

The drawing diagrammatically illustrates two embodiments of an apparatus for carrying out the method according to the invention.

Fig. 1 is a vertical sectional view of a press in which a blank may be subjected both to the preliminary and the final shaping operation.

Figs. 2 and 3 are similar views as Fig. 1 showing the shaping members in two different posi- .tions.

Fig. 4 shows a vertical sectional view along the line IV-IV in Fig. 5 of a press for producing sharply bent corners on the four sides of a rectangular plate.

Fig. 5 is a plan sectional view of the press on the line VV in Fig. 4.

Fig. 6 is a vertical section view corresponding to that of Fig. 4 but showing the parts after completion of the shaping operation.

In the frame or die mechanism I (Fig. 1) cylinders are formed each of which contains a movable plunger or clamping member 2 to which ressure fluid may be supplied.

In the upper cylinder 3 a die mechanism or plunger 4 is movable said plunger 4 operatively supporting within a hollowed out portion thereof an inner plunger or core member 5. Pressure fluid may be supplied to said plunger 4. '5 at the 2. required pressure, andv in the desired sequence. In-the lower cylinderfi a plunger 7 is movable.

A rectangular or square blank 3 is placed on the frame; or die mechanism l between the plungers. 5;; l, whereafter pressure fluidv is supplied to plungers 4 and l. The pressure fluid through bore' 9;reaches:also-plunger 5 and as the pressure onsaid latter exceeds that on plunger 1, said latter 'plunger-is lowered and the blank. 8 is forced into the space between the plungers 2 and subjectedtoa forming operation to impart theretovtheshape illustrated in dotted lines at 8. in Fig. 1 so that a fiat base portion islformed, together with. marginal portions or corners more or lessrounded and with flanged portions or ends-protruding beyond the clamping surfaces of the plungers 5 and l. Thereupon pressu-reflui-dis supp-lied to plungers 2 so that the. marginal. portionsqof the plate are bent to aright angle as shownin Fig. 2. Finally the pressuresuppliedtoplunger I is increased but nottosuch an extentthat it exceeds the combined, pressure on, plungers l; 5, so that plunger l'remains stationary and forms an abutment for the flanged portions of the plate and plungers 5 and l are activated and move upwards through the adjustable clearance a, whereby the material at the rounded corner is up-set to a sharply bent corner. The plungers 2 are still subjected topressure. Thus while plunger 4 acts as an abutment die mechanism, frame I and plungers 2, 5 and co-operate together as a second die mechanism for upsetting the flanged end portion. The operation of the apparatus in the aforesaid sequence enables a sharply bent flange to be produced while at the same time and during the upsetting step the clamping actions on the flat base portion and the flat flanged portion are maintained to prevent internal displacement of the material of the base portion and/ or dimensional change in the inner face surface of the base portion, and to prevent lengthening of the flanged portion, thereby eliminating any tendency of these portions during the upsetting step to become lumpy, uneven, or to form folds in the surfaces thereof.

Now the shaping operation is completed and the pressure on plungers 2, 4 and 5 is relieved, so that the flanged plate is ejected by plunger 1.

Although the drawing shows only two clamping plungers 2 it will be understood, that four clamping plungers may be provided, one for each side of the blank 8.

With the embodiment according to Figs. 1-3 the excess of material needed for producing the desired sharply bent corners is obtained by forming at the plate a broader flange than finally is required.

As shown in Fig. 4 the blank 8 is preliminarily shaped with flanges 10 whereby inclined regions Ii are bent between the flat central portion of the blank and the flanges 10, square portions corresponding to the width of the flanges having been previously removed from the blank by any suitable method to dispose of this excess material. This preliminarily shaped blank is with its flat central portion clamped between the enlarged heads of plungers 5, l and is supported with its flanged marginal portions i on a stationary support [2. Said flanges I0 are also clamped between fluid operated clamping shoes l3 moving in cylinders l4 and the enlarged headof plunger 5. Thereupon the inclined bent region I i is flattened by means of the hollow up-setting punch 3, whereby the corner between the region II and the flange i0 is up-set so that an accumulation of metal in said corner is obtained resulting in a strengthening of said corner.

Within the scope of the invention also only one lateral edge of a blank may be flanged.

What I claim is:

1. A method of producing a sharply bent flange in a metal plate comprising bending to a rounded edge a flat portion of said plate in flanged relation to the base portion of said .plate, clamping said base portion to prevent internal displacement of the material thereof, clamping said flanged portion to prevent dimensional change in the inner face surface of said base portion and to prevent lengthening of said flanged portion, and then while maintaining said clamping actions on said base and flanged portions, applying an upsetting force in the plane of said flange and rounded edge to produce an angular corner.

2. A method of producing a sharply bent flange in a metal plate comprising bending to a rounded edge a flat portion of said plate in flanged relation to the base portion of said plate, clamping 4 said base portion to prevent internal displacement of the material thereof, clamping said flanged portion to prevent lengthening thereof, and then while maintaining said clamping actions on said base and flanged portions, applying an upsetting force in the plane of said flange and rounded edge to produce an angular corner.

3. A method of producing a sharply bent flange in a metal plate comprising bending to a rounded edge a flat portion of said plate in flanged relation to the base portion of said plate, forming an inclined bent region between said flat base portion and said flat flanged portion, clamping said flat base portion to prevent internal displacement of the material thereof, clamping said flanged portionto prevent lengthening thereof, and then while maintaining said clamping actions on said base and flanged portions, applying an upsetting force in the plane of said flange and rounded edge to flatten said inclined bent region and to produce an angular corner.

BEREND J. VOSLAMBER.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Country Date Germany Nov. 18, 1901 Number Re. 19,927 265,431 671,427 874,831 1,388,888 1,388,889 1,439,352 1,503,884 1,619,549 1,663,316 1,690,917 2,423,432.

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